From: "Paul E. McKenney" <paulmck@kernel.org>
To: rcu@vger.kernel.org
Cc: linux-kernel@vger.kernel.org, kernel-team@fb.com,
rostedt@goodmis.org, Alison Chaiken <achaiken@aurora.tech>,
"Paul E . McKenney" <paulmck@kernel.org>
Subject: [PATCH rcu 05/10] rcu: Move kthread_prio bounds-check to a separate function
Date: Fri, 4 Feb 2022 15:24:01 -0800 [thread overview]
Message-ID: <20220204232406.814-5-paulmck@kernel.org> (raw)
In-Reply-To: <20220204232355.GA728@paulmck-ThinkPad-P17-Gen-1>
From: Alison Chaiken <achaiken@aurora.tech>
Move the bounds-check of the kthread_prio cmdline parameter to a new
function in order to faciliate a different callsite.
Signed-off-by: Alison Chaiken <achaiken@aurora.tech>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
---
kernel/rcu/tree.c | 39 +++++++++++++++++++++++----------------
1 file changed, 23 insertions(+), 16 deletions(-)
diff --git a/kernel/rcu/tree.c b/kernel/rcu/tree.c
index 4e5e37e5ee3c9..5bf0312f66760 100644
--- a/kernel/rcu/tree.c
+++ b/kernel/rcu/tree.c
@@ -4440,26 +4440,10 @@ static int rcu_pm_notify(struct notifier_block *self,
static int __init rcu_spawn_gp_kthread(void)
{
unsigned long flags;
- int kthread_prio_in = kthread_prio;
struct rcu_node *rnp;
struct sched_param sp;
struct task_struct *t;
- /* Force priority into range. */
- if (IS_ENABLED(CONFIG_RCU_BOOST) && kthread_prio < 2
- && IS_BUILTIN(CONFIG_RCU_TORTURE_TEST))
- kthread_prio = 2;
- else if (IS_ENABLED(CONFIG_RCU_BOOST) && kthread_prio < 1)
- kthread_prio = 1;
- else if (kthread_prio < 0)
- kthread_prio = 0;
- else if (kthread_prio > 99)
- kthread_prio = 99;
-
- if (kthread_prio != kthread_prio_in)
- pr_alert("rcu_spawn_gp_kthread(): Limited prio to %d from %d\n",
- kthread_prio, kthread_prio_in);
-
rcu_scheduler_fully_active = 1;
t = kthread_create(rcu_gp_kthread, NULL, "%s", rcu_state.name);
if (WARN_ONCE(IS_ERR(t), "%s: Could not start grace-period kthread, OOM is now expected behavior\n", __func__))
@@ -4584,6 +4568,28 @@ static void __init rcu_init_one(void)
}
}
+/*
+ * Force priority from the kernel command-line into range.
+ */
+static void __init sanitize_kthread_prio(void)
+{
+ int kthread_prio_in = kthread_prio;
+
+ if (IS_ENABLED(CONFIG_RCU_BOOST) && kthread_prio < 2
+ && IS_BUILTIN(CONFIG_RCU_TORTURE_TEST))
+ kthread_prio = 2;
+ else if (IS_ENABLED(CONFIG_RCU_BOOST) && kthread_prio < 1)
+ kthread_prio = 1;
+ else if (kthread_prio < 0)
+ kthread_prio = 0;
+ else if (kthread_prio > 99)
+ kthread_prio = 99;
+
+ if (kthread_prio != kthread_prio_in)
+ pr_alert("%s: Limited prio to %d from %d\n",
+ __func__, kthread_prio, kthread_prio_in);
+}
+
/*
* Compute the rcu_node tree geometry from kernel parameters. This cannot
* replace the definitions in tree.h because those are needed to size
@@ -4744,6 +4750,7 @@ void __init rcu_init(void)
kfree_rcu_batch_init();
rcu_bootup_announce();
+ sanitize_kthread_prio();
rcu_init_geometry();
rcu_init_one();
if (dump_tree)
--
2.31.1.189.g2e36527f23
next prev parent reply other threads:[~2022-02-04 23:24 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-02-04 23:23 [PATCH rcu 0/10] Real-time-related updates for v5.18 Paul E. McKenney
2022-02-04 23:23 ` [PATCH rcu 01/10] rcu: Mark accesses to boost_starttime Paul E. McKenney
2022-02-04 23:23 ` [PATCH rcu 02/10] rcu/nocb: Handle concurrent nocb kthreads creation Paul E. McKenney
2022-02-04 23:23 ` [PATCH rcu 03/10] rcu: Remove unused rcu_state.boost Paul E. McKenney
2022-02-04 23:24 ` [PATCH rcu 04/10] rcu: Create per-cpu rcuc kthreads only when rcutree.use_softirq=0 Paul E. McKenney
2022-02-04 23:24 ` Paul E. McKenney [this message]
2022-02-04 23:24 ` [PATCH rcu 06/10] rcu: Make priority of grace-period thread consistent Paul E. McKenney
2022-02-04 23:24 ` [PATCH rcu 07/10] rcu: Elevate priority of offloaded callback threads Paul E. McKenney
2022-02-04 23:24 ` [PATCH rcu 08/10] rcu: Update documentation regarding kthread_prio cmdline parameter Paul E. McKenney
2022-02-04 23:24 ` [PATCH rcu 09/10] rcu: Don't deboost before reporting expedited quiescent state Paul E. McKenney
2022-02-04 23:24 ` [PATCH rcu 10/10] rcu: Add per-CPU rcuc task dumps to RCU CPU stall warnings Paul E. McKenney
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